In a cassette-type tape player, a play mode for reproduction or recording is created by engagement of two reel shafts vertically standing on a base plate with shaft bores of a tape cassette. To effect this engagement, various methods are employed depending on whichever direction a cassette is inserted into the tape player. One of the methods is horizontal loading wherein a cassette is horizontally inserted into a pack guide through an insertion opening formed in a front face of a tape player and the pack guide carrying the tape pack is thereafter dropped so that the shaft bores of the tape cassette engage the reel shafts.
In this type of tape player, the pack guide cannot be dropped before the cassette is fully inserted into the pack guide because the reel shaft cannot meet the shaft bores but instead hits the lower face of the tape cassette. It is difficult, however, to fully insert the tape cassette by a finger because the insertion opening is generally as small as the sectional area of the tape cassette and does not permit insertion of a finger, or alternatively, if a finger is inserted through the insertion opening, it may be caught in the tape player when the pack guide drops.
In this connection, there is used a loading mechanism which automatically pulls a halfway manually inserted tape cassette fully into the pack guide. For such loading power, motor driving force or spring force is employed. One type of such loading mechanism employs a single inversion spring which pulls a cassette intc the play position and also ejects it therefrom.
FIG. 1 shows a loading and ejection mechanism employing such inversion spring. A guide arm 2 which supports a pack guide 1 is formed on an upper plate thereof with a guide groove 3 extending from front to rear of the tape player and slidably receiving therein a pack stopper 4. A shaft 4a formed on the pack stopper 4 is connected by a torsion-type inversion spring 6 to one end of an ejection link 5 which is also linked to the pack guide 1. One end of the inversion spring 6 connected to the shaft 4a is configured in a circle rotatable about the shaft 4a whereas the other end is rotatably inserted into a bore formed at said end of the link 5. The other end of the link 5 is pivotally supported by an axle 7. The middle of the link 5 is connected to an ejection member 8 by an operation rod 9. The ejection lever 8 is connected to a projection 10 of a frame of the tape player by the revival spring 11.
With this arrangement, if a tape cassette is manually inserted halway into the pack guide 1, it pushes and shifts the pack stopper 4 rearward (to the right in the Figures) of the tape player. The inversion spring 6 is urged to decrease the angle made by the two arms thereof, accordingly. As shown by FIG. 2, when the pack stopper 4 conveys the associated end of the inversion spring 4 behind (to the right of, in the Figures) the other end of the same, i.e. when the shaft 4a of the pack stopper 4 comes behind the front (left, in the Figures) end of the link 5, expansion force of the inversion spring 6 is oriented rearward with respect to said one end of the link 5 which stands still. Due to this expansion force, the pack stopper 4 is urged rearward together with the cassette engaging therewith, thereby effecting automatic loading.
To eject out the tape cassette, the ejection member 8 is manually pushed in. As shown by FIG. 3, the link 5 is urged by the ejection member 8 via the operation rod 9 and rotates about the axle 7 in the counterclockwise direction. The connected end of the inversion spring 6 is therefore compressed and comes behind the other end linked to the pack stopper 4. As the result, expansion force of the inversion spring 6 is directed frontward and urges the pack stopper 4 and the cassette engaging therewith frontward of the tape player. The ejection member 8 is thereafter returned to its original position by the revival spring 11 and causes rearward displacement of the link 5 and the pack stopper 4 connected thereto via the inversion spring 6, thereby effecting automatic ejection of the tape cassette from the pack guide 1.
Thus, the inversion spring type loading and ejection mechanism uses the revival force of the inversion spring which is selectively oriented rearward or frontward of the tape player, depending upon changes of positional relation between the front end of the link 5 and the shaft 4a of the pack stopper 4, thereby effecting automatic full insertion of the tape cassette manually halfway inserted into the pack guide 1 or effecting automatic ejection of the tape cassette from the fully inserted position to the halfway inserted position.
This type of prior art loading and ejection mechanism, however, involves some problems. Namely, it is only the revival spring 11 that gives the force for pulling out the slightly frontward shifted tape cassette to the ejected position. However, because the ejection force must overcome the friction between the tape cassette and the inner wall of the pack guide 1 or the resistance of a dust protection door covering the cassette insertion opening of the escutcheon, the revival spring 11 must be large. If the revival spring 11 is large, a considerably large manual force is required to compress it upon ejecting operation. Particularly at the beginning of the ejecting operation, the manual force must be so large as to also overcome the expansion force of the inversion spring 6 in addition to the revival spring 11.
A further problem of the prior art mechanism is the operative linkage between the ejection member 8 and the pack stopper 4. Namely, since the ejection member 8 and the pack stopper 4 are disposed for simultaneous movement, the cassette is not pulled out of the pack guide 1 merely by the insertion of the ejection member 8. It is ejected out only when the ejection member 8 is released from the manual force and the revival spring 11 is allowed to return to its original length. Therefore, this gives an impression that the ejecting motion is somewhat slow.